Robotic vacuum cleaners comprising side arms are known. Side arms of this kind carry a side brush by means of which a region reached by the robotic vacuum cleaner in each case can be enlarged. It is known that robotic vacuum cleaners generally have a round or at least substantially round basic shape which means that corners are difficult to reach. Dust or other impurities in said corners cannot be easily reached by the robotic vacuum cleaner, meaning that the cleaning result is unsatisfactory, at least in this respect. Side arms which are laterally arranged on the robotic vacuum cleaner and extend beyond the outer periphery of the housing of the robotic vacuum cleaner, and typically rotating side brushes fixed there, serve to also reach such corners or other border regions of the floor worked by the robotic vacuum cleaner in each case.
Longer side arms or longer bristle clusters on the side brushes compared with previous solutions make it possible, in principle, to also better reach the deeper portions, for example of a corner. However, the bristle clusters of the side arms may not exceed a certain length, because there is otherwise the risk that the brush filaments which the bristle clusters comprise would enter the drive wheels of the robotic vacuum cleaner or the central bristle roller associated with the suction mouth for example. The length of the side arms is also restricted, at least by practical considerations, since, during operation, the robotic vacuum cleaner has to avoid collisions with obstacles in the form of walls, doors and furniture, or has to change its direction of travel in the event of such collisions. A collision which is typically to be avoided or a collision requiring a change of direction may occur on account of the side arms.
WO 2013/051843 A1 discloses a robotic vacuum cleaner comprising two side arms which can be moved from a position in the housing into a working position in which they are pivoted out. In this respect, WO 2013/051843 A1 describes two embodiments, specifically an embodiment in which the outward pivoting is brought about by motors, and a further embodiment in which the outward pivoting is brought about by means of a spring mechanism. Using the spring mechanism, the respective side arm is pivoted out of its position in the housing of the robotic vacuum cleaner and is held in the outwardly pivoted state by means of tensile loading. In the event of a side arm making contact with an obstacle, the side arm can be pressed back into the housing against the spring tension. WO 2013/051843 A1 does not appear to contain any considerations for the event of a collision in the variant in which the side arms are extended by means of motors.
In the case of the side arms movable by the spring mechanism in WO 2013/051843 A1, outward pivoting and inward pivoting in the event of a collision is entirely conceivable. However, the inward pivoting appears to be possible only in a collision situation during a forward movement or at least only in the event of contact of an edge of the side arm at the front in the outward pivoting direction with an obstacle. If, on the other hand, the side arm strikes an obstacle with the edge thereof at the rear in the outward pivoting direction, the force resulting from the collision with the obstacle acts in the outward pivoting direction and thus directly prevents inward pivoting of the side arm and elimination of the collision situation. However, this type of contact of the edge of a side arm at the rear in the outward pivoting direction with an obstacle is possible at any time during a rotational movement of the robotic vacuum cleaner for example. In such a case, the robotic vacuum cleaner proposed in WO 2013/051843 A1 appears to be unable to continue a started rotational movement. The motor-driven side arms of WO 2013/051843 A1 appear to be problematic in the event of a collision with an obstacle, regardless of a respective rotational direction.